Materials deteriorate in different ways. Some get moldy (bread), some dry out and crack (wood), some go sour (milk), some rust (steels), etc. In the case of food it is micro-organisms that cause it to go bad. When we preserve materials we can prolong its lifespan or in some cases prevent it from deteriorating.

This activity will show us one method of preserving a food material:

You need:

One slice of bread.

A knife

Either an oven, grill, braai coals (something that gives off high heat)

Some information: Drying is process of removing water (moisture) from a material. In drying the moisture that comes out is not used, i.e. it goes up into the air. One way to remove moisture is by applying heat.